MY BIGGEST PROBLEM in capacitance

[meLzee]

Homework Statement

THREE CAPACITORS HAVING CAPACITANCE 8.4 F, 8.4 F, 4.2 F ARE CONNECTED IN SERIES ACROSS A 36 V POTENTIAL DIFFERENCE. THE CAPACITORS ARE DISCONNECTED FROM THE POTENTIAL DIFFERENCE WITHOUT ALLOWING THEM TO DISCHARGE. THEY ARE THEN RECONNECTED IN PARALLEL WITH EACH OTHER, WITH THE POSITIVELY CHARGED PLATES CONNECTED TOGETHER. WHAT IS THE VOLTAGE ACROSS EACH CAPACITOR IN PARALLEL COMBINATION?

PLEASE HELP ME WITH THIS. THANX.

 

[Andrew Mason]

Homework Statement

THREE CAPACITORS HAVING CAPACITANCE 8.4 F, 8.4 F, 4.2 F ARE CONNECTED IN SERIES ACROSS A 36 V POTENTIAL DIFFERENCE. THE CAPACITORS ARE DISCONNECTED FROM THE POTENTIAL DIFFERENCE WITHOUT ALLOWING THEM TO DISCHARGE. THEY ARE THEN RECONNECTED IN PARALLEL WITH EACH OTHER, WITH THE POSITIVELY CHARGED PLATES CONNECTED TOGETHER. WHAT IS THE VOLTAGE ACROSS EACH CAPACITOR IN PARALLEL COMBINATION?

PLEASE HELP ME WITH THIS. THANX.

What work have you done so far? Can you write the relationship between C, Q and V? How do you determine C for three capacitors in series? In parallel?

AM

 

[meLzee]

C = Q/V

i got confused on how to solve their own voltages. i mean is the total voltage when they are connected in series. the same as when they are connected then in parallel?

 

[rl.bhat]

When three capacitors are connect in series, what is the resultant capacitance of the combination? In the series combination, each capacitor has the same charge.
When they are connected in parallel, you know the total charge. You can find the resultant capacity of the parallel combination. From that you can find the common voltage.